Cabinet joint



July 23, 1968 R. T. CORNELIUS CABINET JOINT Filed Feb. 20, 1967 UnitedStates Patent O 3,393,933 CABINET JOINT 'Richard T. Cornelius,Minneapolis, Minn., assigner to The Cornelius Company, Anoka, Minn., acorporation of Minnesota Filed Feb. 20, 1967, Ser. No. 622,012 18Claims. (Cl. 287-489.136)

ABSTRACT F THE DISCLOSURE BACKGROUND OF THE INVENTION Field of theinvention This invention pertains to structure employed to join togetherand to conceal a joint between two metal sheets in a cabinet.

Description of the prior art Heretofore, it has been conventional tojoin `metal sheets together in various ways, such as by spot-welding, orsuch as by means of removable nuts and bolts. The former has thedisadvantage that there must be an electrically clean connection betweenthe sheets to be joined in order to obtain reliability in the productionof spot-welds therebetween, and such reliability is not `obtainable ifone of the sheets has been pre-finished with a non-electricallyconducting coating. The latter has the disadvantage that separate boltsmust be employed, or their equivalents such as rivets, the use of whichnecessitates provision of aligned holes in the two workpieces.

Summary of the invention The present invention contemplates that anumber of ears are struck integrally out of one of the sheet metal partsand caused to project into the other to preclude relative movementtherebetween in at least one axis, thereby enabling the use ofpre-painted or pre-nished material and obviating the need for providinghole-receiving fasteners such as screws or rivets, such joint beingenclosed `and concealed by a trim strip of U-shaped cross section whichreceives the joint, and which has a shoulder which snaps over the earthus produced to preclude separation of such trim strip therefrom.

Accordingly, it is an object of the present invention to provide acabinet joint enabling the use of pre-finished sheet materials whileeliminating the need for any separate fasteners.

Another object of the present invention is to provide a cabinet jointconstruction having a nished appearance at a minimum of cost in laborand materials.

Many other advantages, features and additional objects of the presentinvention will become manifest to those versed in the art upon makingreference to the detailed description an dto the accompanying sheet ofdrawings in which a preferred structural embodiment incorporating theprinciples of the present invention is shown by way of illustrativeexample.

On the drawings:

FIG. 1 is a side elevational view, partly broken away, of a cabinetprovided in accordance with the principles of the present invention;

ICC

FIG. 2 is an enlarged fragmentary cross-sectional view taken along lineII-II of FIG. 1;

FIG. 3 is a top View in reduced scale of the cabinet shown in FIG. lduring assembly thereof;

FIG. 4 is an enlarged fragmentary view of a portion shown within acircle IV on FIG. 3;

FIG. 5 is a bottom view of the structure shown in FIG. 4;

FIG. 6 illustrates fabrication of the trim strip; and

FIG. 7 is an enlarged cross-sectional view of the trim strip shown inFIG. 2 in its unassembled state.

As shown on the drawings: I

The principles of this invention are particularly useful when embodiedin a joint in a sheet metal cabinet such as shown in FIG. 1, generallyindicated by the numeral 1t?. As best seen in FIG. 3, the cabinetincludes a pair of side sections 11, 12, the side section 11 extendingalong the front of the cabinet and along opposite ends to meet thesimilarly extending side section 12 which extends along the rear andalong such ends. The cabinet 10 includes a bottom 13 to which a numberof feet 14 may be directly or indirectly secured. The side sections 11,12 are jointly referred to herein as a metal sheet, and they maycomprise a single such sheet. Where the side sections 11, 12 compriseseparate sheets, they are joined together at their abutting seam 15 bymeans not shown herein nor necessary to an understanding of the presentinvention. The bottom sheet 13 is likewise also referred to herein as ametal sheet. The sheet 13 is joined to the sheet 11, 12 by means of acabinet joint 16 best shown in FIGS. 2 and 5.

The sheet 11, 12 has a lower marginal portion 17 which extends about thelower perimeter of the cabinet 11 while the sheet 13 has a down-turnedflange 18 which extends about its perimeter and which likewise comprisesa marginal portion which is disposed in abutting relation to themarginal portion 17. In the practice of this invention, either side ofthe sheet 11 or either side of the sheet 13 may be predinished, and thejoint 16 may be applied thereto without damage to such finish.

The joint 16 further includes an ear 19 which is integral with themarginal portion 1'7 of the sheet 11 and which extends through anaperture (not shown) in the marginal portion 18 of the sheet 13 suchaperture being formed by the formation of a second ear 20 out of themarginal portion 13 thereof. The ear 19 is thus integral with the sheet11 and projects from its surface while the ear 20 is integral with themarginal portion 18 of the sheet 13 immediately adjacent to the ear 19,the ear 20 projecting in a parallel position and in engagement with theear 19. Both of the ears 19 and 20 are elongated and are integral at atleast one and preferably both ends with the respective sheets 11, 13,and Iboth ears 19, 20l are severed along their length, preferably alongopposite sides thereof, and are bowed intermediate their ends, all asillustrated. The upper and lower edges of the ear 19 are thus engaged byconfronting edges that dene the aper ture in the flange 18 of theadjacent sheet for the purpose of transmitting a supporting forcetherebetween. It is thus evident that the ear 19 projects snugly throughan aperture in the flange 18 of the sheet 13.

A number of cabinet joints 16 are provided as shown in FIG. 3, therebeing 18 joints with the sheet 13 in this embodiment. Once these havebeen provided as shown in FIG. 3, the cabinet is then ready for thereception of a molding strip 21 shown in assembled relation to the pairof metal sheets in FIGS. 1 and 2.

The construction of the molding strip 21 is best understood :byreferring preliminarily to FIIG. 6. A strip of metal of considerablelength has marginal edges 22, 23 and a uniformly spaced series ofapertures 24 which ex- 3 tend almost from the edge 22 to the edge 23.Over this strip there is molded plastic material 24 of suitableconfiguration, and then marginal portions of the metal strip are removedleaving a pair of ultimate edges 25, 26. These edges 25, 26 extendthrough the slits Z4 so as to leave a series of separate elements 27 ofuniform size and uniform spacing embedded in the strip. The strip isthen bent along two longitudinal lines so as to form the molding strip21 with a cross section as shown in FIG. 4.

As best seen in FIG. 7, the molding strip 21 thus comprises plastic 24of U-shaped cross section having a leg portion 28 and a leg portion 29and a closed end 30. A leg portion 29 has a resilient flange 31 whichcarries an internal shoulder 32 directed or facing generally toward theclosed end 30 of the Ushape. The flange 31 is secured to an internalsurface of the strip 21 on the leg portion 29. The resilient llange 31tapers on both sides of the shoulder 32, the flange thickness increasingas it extends toward the inner surface of the leg portion 29, and thethickness decreasing in a tapered fashion in the opposite direction.Thus the strip has an internal spring which comprises a series ofseparate U-shaped elements 27 disposed along the length of the strip.The leg portions of the spring terminate at the edges 25, 26 which aresubstantially coplanar with the ends of the leg portions 28, 29 of thestrip.

The internal shoulder 32 defines a gap 33 `with the inner surface of theopposite leg portion, the gap being smaller than the combined thicknessof the sheets at their marginal portions 17, 18, such gap 33 receivingthe marginal portions 17, 18 as shown in FIG. 2. However, the ear, inthis instance the ear 20, snaps past the shoulder 32 to hold the moldingstrip 21 securely in place. Preferably, the molding strip 21 has alength which is coextensive with the flange 18 so as to enclose theentire lower edge of the sheet 11, 12.

To construct the cabinet joint 16, the pair of metal sheets are held inthe desired ultimate relative position with respect to each other, theear or ears 19, are simultaneously formed, and the molding strip 21 isthen slipped into place as described, the spring elements 27 acting tohold the strip securely in position with the leg portion 28 lirmlyagainst the outer surface of the sheet 11, 12.

Although various minor modifications might be suggested by those versedin the art, it should be understood that I Wish to embody within thescope of the patent warranted hereon all such embodiments as reasonablyand properly come within the scope of my contribution to the art.

I claim as Imy invention:

1. A cabinet joint, including:

(a) a pair of metal sheets having marginal abutting portions joinedtogether, at least one of said sheets having at least one ear integraltherewith and projecting out tof the surface of said one sheet;

(b) a molding strip of U-shaped cross-section receiving said marginalportions within said U-shape, said strip having an internal shoulderdirected toward the closed end of said U-shape in engagement with anoppositely facing edge of said ear.

2. A cabinet joint according to claim 1, in 'which said marginal portionof one sheet comprises a flange extending around said sheet, said stripbeing coextensive in length with said flange.

3. A cabinet joint according to claim 1, the other of said sheets havingan ear integral therewith at each of said ears in said one sheet, andprojecting in a parallel position therewith.

4. A cabinet joint according to claim 1, in which an edge of said ear isengaged yby an edge of the adjacent sheet for transmitting a supportingforce therebetween.

5. A cabinet joint according to claim 1, in which each said ear iselongated, is integral at both its ends with said sheets, is severedfrom said sheet along its length, and is bowed along its length.

6. A cabinet joint according to claim 5, in which each said ear issevered from said sheet along opposite sides or" its length.

7. A cabinet joint according to claim 1, in which each of said sheetshave at least one of said ears, in parallel engagement with each other,each of said ears being elongated and integral with said sheetsrespectively at at least one of its ends, and being severed from saidsheet opposite sides of its length.

8. A cabinet joint according to rclaim 6, in which each of said sheetshave at least one of said ears in parallel engagement with each other,one of Said ears projecting through one of said sheets for being engagedby an edge thereof.

9. A cabinet joint according to claim 1, in which said internal shoulderis carried on a resilient flange secured to an internal surface of saidmolding strip.

1d. A cabinet joint according to claim 9, in which said internalshoulder and the opposite inner side of said mold ing strip dene a gapwhich in its unassembled form is smaller than the thickness of saidsheets at said ear.

11. A cabnet joint according to claim 1, in which the thickness of saidflange tapers on at least one side of said shoulder.

12. A cabinet joint according to claim 11, in which the thickness ofsaid flange tapers increasingly from said shoulder toward said internalsurface and tapers decreasingly from said shoulder toward the oppositedirection.

13. A cabinet joint according to claim 1, in which said molding stripcomprises plastic, and has an internal spring of U-shaped cross-sectionaligned with the cross-section of said strip.

14. A cabinet joint according to claim 13, in which the leg portions ofthe U-shaped plastic strip terminate substantially with the leg portionsof the U-shaped spring.

15. A cabinet joint according to claim 13, in which the U-shaped springcomprises a series of separate elements disposed along the length ofsaid strip.

16. A cabinet joint according to claim 14, in which the U-shaped springcomprises a series of separate elements disposed along the length ofsaid strip.

17. A cabinet joint according to claim 12, in which said molding stripcomprises plastic, and has an internal spring of U-shaped cross-Sectionaligned with the crosssection of said strip, the leg portions of theU-shaped plastic strip and of the U-shaped spring terminating together,said U-shaped Spring comprising a series of separate elements disposedalong the length of said strip.

18. A cabinet joint according to claim 17, in which each of said sheetshave at least one of said ears in parallel engagement with each other,one of said ears projecting through one of Said sheets for being engagedby an edge thereof, each of said ear being elongated and integral atboth of its ends with one of said sheets and being severed therefromalong opposite sides of its length, and being bowed along its length.

References Cited UNITED STATES PATENTS 2,295,893 9/1942 Detrich287-189.36 3,128,002 4/1964 Buchanan 220-80 XR 3,297,384 l/l967 Buice312-263 3,327,893 6/1967 Graves 24S-345.1 XR

JOHN PETO, Primary Examiner'.

